RX610 Group
11. Buses
R01UH0032EJ0120 Rev.1.20
Page 290 of 1006
Feb 20, 2013
11.5.1.2
Page Access
When the PRENB and PWENB bits in CSiMOD are set to 1 to enable page-reading and page-writing access, respectively,
the bus access for page access operations becomes page reading and writing. Page access is made when two or more
rounds of external bus access are required for a single transfer request from the bus master. See figures 11.15 to 11.18 for
the conditions under which page access occurs.
D0
D1
A0
A1
Page read cycle wait
(CSPRWAIT)
Read cycle wait
(CSRWAIT)
Read-access CS extension
cycle (CSROFF)
RD assert wait (RDON)
RD assert wait (RDON)
*
CS assert wait (CSON)
Tw1
Tpw1
Tnm
Tpwn
Tn1
Tw2
Tend
Tend
Th
Twn
Data bus
(D15 to D0)
External bus clock
(BCLK)
Address
(A23 to A0)
Chip select/byte control
(CSn#/BC0#, BC1#)
[Legend] n = 0 to 7
Data read
(RD#)
Next bus access can be started
Note:
*
The RD assert wait operation in the second and subsequent bus accesses depends on the page read
access mode setting.
Figure 11.15 Page-Read Access Timing